Pierre Shale
Stratigraphic range: Campanian-Maastrichtian
A broken concretion with fossils inside; Late Cretaceous Pierre Shale near Ekalaka, Montana
TypeGeological formation
Sub-unitsFrom oldest to youngest:[1]
  • Gammon Ferruginous Member
  • Sharon Springs Member
  • Mitten Black Shale Member
  • Red Bird Silty Member
  • A lower unnamed shale member
  • Kara Bentonitic Member
  • Upper unnamed shale member
UnderliesFox Hills Formation
OverliesNiobrara Formation
Lithology
PrimaryShale
Location
Coordinates44°23′42″N 100°24′43″W / 44.395°N 100.412°W / 44.395; -100.412
RegionNorth America
Country United States,
 Canada
Type section
Named forFort Pierre
Named byMeek & Hayden, 1862
Pierre Shale is located in the United States
Pierre Shale
Pierre Shale (the United States)
Pierre Shale is located in South Dakota
Pierre Shale
Pierre Shale (South Dakota)
Baculites from the Pierre Shale showing sutures and remnant aragonite; western South Dakota, Late Cretaceous.

The Pierre Shale is a geologic formation or series in the Upper Cretaceous which occurs east of the Rocky Mountains in the Great Plains, from Pembina Valley in Canada[2] to New Mexico.

The Pierre Shale was described by Meek and Hayden in 1862 in the Proceedings of the Academy of Sciences (Philadelphia). They described it as a dark-gray shale, fossiliferous, with veins and seams of gypsum, and concretions of iron oxide. The Pierre Shale is about 3,138 feet (956m) thick at the type locality. It overlies the Niobrara division and underlies the Fox Hills beds.[1] It was named for an occurrence near Fort Pierre on the Missouri River in South Dakota.[3]

The Pierre Shale is of marine origin and was deposited in the Western Interior Seaway. It is correlative with other marine shales that occur farther west, such as the Bearpaw Shale, Mancos Shale and the Lewis Shale.[4] It correlates with the Lea Park Formation in central Alberta.[5] The Pierre is overlain by marginal marine deposits of the Fox Hills Formation.

Most of the formation was deposited in the Campanian Age of the late Cretaceous. However, the discovery of fossils of Baculites baculus in the uppermost beds of the Pierre Shale in the Raton, New Mexico area show that deposition continued here into the early Maastrichtian.[6]

Mineral resources

The Pierre Shale is the host formation for commercial petroleum deposits in the Florence and Canon City fields in Fremont County, Colorado, and the Boulder Oil Field in Boulder County, Colorado. More recently, natural gas has been extracted in the Raton Basin in southern Colorado. The shale formation is usually too impermeable for hydrocarbon extraction, but produces in areas where it is naturally fractured or fractured by artificial means.

Paleofauna

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Reptiles

Dinosaurs

Birds reported from the Pierre Shale Formation
Genus Species Location Stratigraphic position Material Notes Images

Brodavis

B. varneri

South Dakota

Sharon Springs Member.[7]

A hesperornithiform.

B. sp.

Manitoba

Pembina Member.[7]

A hesperornithiform.

Hesperornis

H. bairdi

South Dakota

Sharon Springs Member.[7]

A hesperornithid.

H. chowi

Manitoba & South Dakota

Pembina, Millwood, & Sharon Springs Members.[7]

A hesperornithid.

H. lumgairi

Manitoba

Pembina Member.[7]

A hesperornithid.

H. macdonaldi

Manitoba & South Dakota.

Gammon, Pembina, Millwood(?), & Sharon Springs Members.[7]

A hesperornithid.

H. mengeli

Manitoba & South Dakota.

Pembina & Sharon Springs Members.[7]

A hesperornithid.
H. regalis

Manitoba, South Dakota, & Kansas

Gammon, Pembina, & Sharon Springs Members.[7][8]

A hesperornithid.
H. sp. Manitoba.[8] Pembina Member.[8] Probably referrable to H. regalis, but indistinguishable from H. crassipes.[8]
Hesperornithidae Gen. et. sp. indeterminate Manitoba.[8] Pembina Member.[8] Multiple isolated synascra.[8] A hesperornithid.
Hesperornithiformes Fam., gen. et sp. indet. Manitoba.[8] Pembina Member.[8] Multiple vertebrae, phalanges, tibiotarsal fragments and a fibula.[8]
Ichthyornis I. sp. Manitoba.[8] Pembina Member.[8] "MDM B77.03.07 (vertebral centrum), B80.05.14 (femur)".[8] An ichthyornithe.
Ornithischians reported from the Pierre Shale Formation
Genus Species Location Stratigraphic position Material Notes Images
Claosaurus C. affinis South Dakota.[9] "Pedal phalanx (lost)."[10] Currently considered dubious.

Mosasaurs

Mosasaurs reported from the Pierre Shale Formation
Genus Species Location Stratigraphic position Material Notes Images
Clidastes C. propython Manitoba.[8] Pembina Member.[8] MDM M74.10.06 (skull, mandible, vertebral column).[8] A mosasaurine also known from the Mooreville Chalk.
Western Kansas.[11] Vertebrae associated with 'Plesiosaurus' gulo currently lost.[12] Likely represents the stomach contents of 'Plesiosaurus' gulo.[12]
Globidens G. dakotensis South Dakota.[13] Sharon Springs Member.[13] FMNH PR 846.[13] A globidensin.
G. schurmanni At the Big Bend of the Missouri River, Buffalo County, South Dakota.[14] Uppermost DeGrey Formation.[14] "SDSM 74764, partial anterior skeleton, including cranium, jaws, cervical and trunk vertebrae partially articulated, pectoral girdles, partial anterior paddle, isolated humerus and ulna, and isolated caudal vertebrae".[14]
G. sp. Northwestern Logan County, Kansas.[13] Upper level of the Sharon Springs Member.[13] A nearly complete right dentary (FHSM VP–13828).[13] A globidensin.
Hainosaurus H. pembinensis Near Morden, Manitoba.[15] Pembina Member.[8][15] Reassigned to the genus Tylosaurus.
Jormungandr J. walhallaensis Cavalier County, North Dakota.[16] Pembina Member.[16] Partial skull & skeleton.[16] A mosasaurine.
Latoplatecarpus L. nichollsae "19 km northwest of Morden, Manitoba".[17] Pembina Member.[17] A skeleton (CMN 52261).[17] A plioplatecarpine.
Mosasauridae Subfam., gen. et. sp. indeterminate Manitoba.[8] Pembina Member.[8] Fragmentary specimens consisting "mostly of vertebral scraps, ribs and flipper elements".[8]
Platecarpus P. coryphaeus Pembina Member.[8] Now deemed synonymous with P. tympaniticus.
P. ictericus Pembina Member.[8] Now deemed synonymous with P. tympaniticus.
P. somenensis Pembina Member.[8] Found to nest within Latoplatecarpus nichollsae.
P. tympaniticus Pembina Member.[8] Abundant specimens.[8] A pliopatecarpine and the most abundant mosasaur of the Pierre Shale.
P. sp. Manitoba.[8] Pembina Member.[8] "Isolated skull elements, humeri and pectoral girdles".[8] Probably referrable to P. tympaniticus based on size, but size alone is deemed insufficient for species identification.[8]
Plioplatecarpinae Gen. et. sp. indeterminate Manitoba.[8] Pembina Member.[8] Poorly preserved and unprepared remains.[8]
Plioplatecarpus P. nichollsae "19 km northwest of Morden, Manitoba".[17] Pembina Member.[17] A skeleton (CMN 52261).[17] Reassigned to the genus Latoplatecarpus.[18]
Prognathodon P. overtoni South Dakota.[19] Virgin Creek Member.[19] KUVP 950 (the holotype for the species) and SDSM 3339.[19] A mosasaurine also found in the Bearpaw Shale.
Tylosaurinae Gen. et. sp. indet. Manitoba.[8] Pembina Member.[8] Isolated limb and girdle elements (MDM M74.28.05, M75.20.06, M82.13.17, M84.09.18).[8]
Tylosaurus T. pembinensis Near Morden, Manitoba.[15] Pembina Member.[15] A tylosaurine.
T. proriger Manitoba.[8] Pembina Member.[8] MDM M77.17.07 quadrate, FMNH PR 591 quadrate, pubis, vertebrae.[8] A tylosaurine.

Plesiosaurs

Plesiosaurs reported from the Pierre Shale Formation
Genus Species Location Stratigraphic position Material Notes Images
Alzadasaurus A. pembertonii South Dakota.[8] Sharon Springs Member.[8] Complete specimen (SDSM 451).[8] Synonymized with Styxosaurus snowii.
cf. A. pembertonii Manitoba.[8] Pembina Member.[8] A specimen consisting of two femora, one humerus, two epipodials, fragments of the pelvic girdle and 14 vertebrae (MDM P83.02. 18).[8] Synonymized with Styxosaurus snowii.
Elasmosauridae Gen. et. sp. indeterminate Manitoba.[8] Pembina Member.[8] Remains undiagnostic at the generic level.[8]
Logan County, Kansas.[20] Upper Sharon Springs Member.[20] KUVP 129744, a specimen associated with 47 gastroliths.[20] An elasmosaurid too fragmentary to identify below the family level.[20]
Elasmosaurus E. platyurus Kansas.[21][22] Sharon Springs member.[21][22] Multiple specimens, including the holotype.[21] An elasmosaurid.
?E. sp. Manitoba.[8] Pembina Member.[8] "An incomplete specimen (TMP P84.162.4), consisting of pelvic girdle, distal end of a propodial, an epipodial and 21 vertebrae".[8]
Martinectes M. bonneri Wyoming & South Dakota.[23][24] Sharon Springs Member and Pembina Member.[8] 2 specimens: an adult (UNSM 50133) and a juvenile (UNSM 55810),[23][24] and several others.[8] A polycotylid.
Plesiosauria Fam., gen. et. sp. indeterminate Pembina Member.[8] "Specimens consisting mostly of ribs, caudal vertebrae, broken girdle plates and phalanges".[8] "Further identification is not possible due to poor preservation and the incomplete nature of the material".[8]
'Plesiosaurus' 'P.' gulo Western Kansas.[11] KUVP 1329 (the original specimen consisted of "eleven cervical, thirteen dorsal, and seven or eight other vertebrae" but now only 3 vertebrae remain).[12] An elasmosaurid associated with the remains of a mosasaur (likely Clidastes), representing the stomach contents of the plesiosaur.[12]
Polycotylidae Gen. et. sp. indeterminate Morden area, Manitoba.[8] Pembina Member.[8] Many isolated vertebrae and partial skull remains.[8] A polycotylid.
Serpentisuchops S. pfisterae Wyoming.[25] Upper half of the upper member.[25] "Specimen GPM5001".[25] A polycotylid.
Styxosaurus S. snowii South Dakota.[8] Sharon Springs Member.[8] Complete specimen (SDSM 451).[8] An elasmosaurid originally reported as Alzadasaurus pembertoni.
cf. S. snowii Manitoba.[8] Pembina Member.[8] A specimen consisting of two femora, one humerus, two epipodials, fragments of the pelvic girdle and 14 vertebrae (MDM P83.02. 18).[8] An elasmosaurid originally reported as cf. Alzadasaurus pembertoni.
Kansas.[20] Sharon Springs Member.[20] NJSM 15435.[20] An elasmosaurid tentatively assigned to the genus Styxosaurus.
Trinacromerum T. bonneri Wyoming & South Dakota.[24] Sharon Springs Member and Pembina Member.[8] 2 specimens: an adult (UNSM 50133) and a juvenile (UNSM 55810),[24] and several others.[8] Now moved to the genus Dolichorhynchops.
T. cf. T. kirki Manitoba.[8] Pembina Member.[8] TMP P84.162.3.[8] A polycotylid.
T. sp. Manitoba.[8] Pembina Member.[8] Many poorly preserved specimens.[8] A polycotylid.

Pterosaurs

Pterosaurs reported from the Pierre Shale Formation
Genus Species Location Stratigraphic position Material Notes Images
Pteranodon P. longiceps Kansas, Wyoming & South Dakota.[26] Sharon Springs Member.[26] A skull and multiple postcranial elements.[26] A pteranodontid.

Turtles

Turtles reported from the Pierre Shale Formation
Genus Species Location Stratigraphic position Material Notes Images
Archelon A. ischyros Along the Cheyenne River in Custer County, South Dakota.[27] A protostegid.
A. sp. Colfax County, New Mexico.[28] 3 carapace fragments (NMMNHP-16079 and P-16104).[28] A protostegid.
Protostega P. sp. Manitoba.[8] Pembina Member.[8] MDM T75.01.06.[8] A protostegid.
Testudines Fam., gen. et sp. indet. Manitoba.[8] Pembina Member.[8] Remains only identifiable as "small turtles", probably referrable to Toxochelys latiremis.[8]
Toxochelys T. latiremis Kansas & Manitoba.[8] Pembina Member.[8]

Fish

Bony fish

Bony fish reported from the Pierre Shale Formation
Genus Species Presence Stratigraphic position Material Notes Images
Apsopelix A. sp. cf. A. anglicus Hughes County, South Dakota.[29] Upper DeGrey Formation.[29] SDSM 77482.[29] A crossognathid.
Bananogmius B. evolutus Manitoba.[8] Pembina Member.[8] An articulated skull (MDM F75.05.06).[8] Reassigned to the genus Pentanogmius.
B. sp. Near Thornhill, Manitoba.[8] Pembina Member.[8] Skull and vertebral column (MMMN V82).[8] Specimen originally identified as Ananogmius sp.[8]
Cimolichthys C. nepaholica Manitoba.[8] Pembina Member.[8] An aulopiform.
Cylindracanthus Hyde County, South Dakota.[29] Verendrye Formation.[29] A rostral spine (SDSM 30638).[29]
Enchodus E. gladiolus Sharon Springs Member.[29] An aulopiform.
E. petrosus Manitoba.[8] Pembina Member and Sharon Springs Member.[8][29] An aulopiform.
E. cf. saevus Manitoba.[8] Pembina Member.[8] FMNH PF 5391 (a dentary, maxilla and palatine).[8] Now a junior synonym of E. petrosus.
E. sp. Manitoba.[8] Pembina Member.[8] 2 isolated vertebrae and isolated palatal fangs.[8] An aulopiform.
Ichthyodectes I. ctenodon Manitoba.[8] Pembina Member.[8] Multiple mandibles and some skull and vertebral material.[8] An ichthyodectid.
Ichthyodectidae Gen. et. sp. indet. Manitoba.[8] Pembina Member.[8] Vertebrae and partial caudal fins.[8] An ichthyodectid not referrable to Xiphactinus but indistinguishable from other ichthyodectid genera.[8]
Pachyrhizodus P. caninus Manitoba.[8] Pembina Member.[8] A skull and anterior portions of the body (MDM F74.04.06), and a right dentary (FMNH PF 5397).[8] A pachyrhizodontid.
P. minimus Manitoba.[8] Pembina Member.[8] FMNH PF 5402.[8] A pachyrhizodontid.
P. sp. Manitoba.[8] Pembina Member.[8] 2 isolated vertebral centra (MMMN V73 ).[8] A pachyrhizodontid.
P. sp. indet. Hughes County, South Dakota.[29] DeGrey Formation.[29] SDSM 77481.[29] A pachyrhizodontid.
Pentanogmius P. evolutus Manitoba.[8] Pembina Member.[8] An articulated skull (MDM F75.05.06).[8] A plethodid, originally reported as Bananogmius evolutus.
Protosphyraena P. gladius Hyde County, South Dakota.[29] DeGrey Formation.[29] SDSM 66288 (major portion of pectoral fin).[29] A pachycormid.
P. sp. Manitoba.[8] Pembina Member.[8] A left premaxilla (FMNH PF 5400).[8] Probably represents P. gladius.
Stratodus S. apicalis Manitoba.[8] Pembina Member.[8] An aulopiform.
Teleostei Order, fam., gen. et. sp. indet. Manitoba.[8] Pembina Member.[8] Mostly vertebrae, but also caudal fins and skulls in some specimens.[8]
Xiphactinus X. audax Manitoba and Lyman County, South Dakota.[8][29] Pembina Member and middle part of the Sharon Springs Member.[8][29] An ichthyodectid.

Cartilaginous fish

Cartilaginous fish reported from the Pierre Shale Formation
Genus Species Presence Stratigraphic position Material Notes Images
Archaeolamna A. kopingensis Western Kansas.[30] Sharon Springs Member.[30] A partial skeleton with articulated teeth.[30] An archaeolamnid.
Cretalamna C. appendiculata Manitoba.[8] Pembina Member.[8] Vertebral centra.[8] A megatoothed shark.
Euselachii Fam., gen. et sp. indet. Near Thornhill, Manitoba.[8] Pembina Member.[8] "Three vertebral centra, 15 mm in diameter".[8] Probably represents Squalicorax, but also indistinguishable from juvenile specimens of Cretalamna.[8]
Squalicorax S. sp. aff. S. kaupi Manitoba.[8] Pembina Member.[8] "MDM S80.01.14 (2 teeth), FMNH PF 5399 (1 tooth)".[8] An anacoracid.

Marine vertebrates

Invertebrates

Annelids

Annelids reported from the Pierre Shale Formation
Genus Species Location Stratigraphic position Material Notes Images
Diploconcha D. sp. Wyoming.[1]

Arthropods

Arthropods reported from the Pierre Shale Formation
Genus Species Location Stratigraphic position Material Notes Images
Dioratiopus D. hearttailensis Butte County, South Dakota.[31] Gammon Ferruginous Member.[31] A longodromitid crab.
Dromiopsis D. kimberlyae Butte County, South Dakota.[32] Lower Pierre Shale.[32] 2 specimens.[32] A dynomenid crab.
Heus H. foersteri Tepee Buttes, South Dakota.[33] A raninid crab.
Hoplitocarcinus? H.? punctatus Tepee Buttes, Colorado.[33] A crab.
Hoploparia H. mickelsoni Butte County, South Dakota.[31] Gammon Ferruginous Member.[31] A lobster.
Limulus L. coffini Fort Collins, Colorado.[34] Rocky Ridge Sandstone Member.[34] Thoracetron.[34] A horseshoe crab.
Necrocarcinus N. davisi Butte County, South Dakota.[31] Gammon Ferruginous Member.[31] A necrocarcinid crab.
Plagiophthalmus P. bjorki Tepee Buttes, South Dakota.[33] A prosopid crab.
Protocallianassa P. russelli Butte County, South Dakota.[31] Gammon Ferruginous Member.[31] A mud shrimp.
Raninella R. manningi Tepee Buttes, South Dakota.[33] A raninid crab.
R. oaheensis Butte County, South Dakota.[31] Gammon Ferruginous Member.[31] A raninid crab.
Rugafarius R. fredrichi Butte County, South Dakota.[31] Gammon Ferruginous Member.[31] A spiny lobster.
Xanthosia X. elegans occidentalis Butte County, South Dakota.[31] Gammon Ferruginous Member.[31] A xanthid crab.
Zygastrocarcinus Z. cardsmithi Carter County, Montana.[35] Groat Sandstone Bed, Gammon Ferruginous Member.[35] A homolid crab.

Bivalves

Bivalves reported from the Pierre Shale Formation
Genus Species Location Stratigraphic position Material Notes Images
Cataceramus? C.? barabini Northeastern New Mexico.[6] An inoceramid.
C.? cf. C. barabini Northeastern New Mexico.[6] An inoceramid.
Chlamys C. (Chlamys) nebrascensis Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] A pectinid.
Cuspidaria C. sp. Bowman County, North Dakota.[36] 6 poorly-preserved, broken, decorticated specimens.[36] A cuspidariid.
Cymbophora C. cf. C. gracilis Bowman County, North Dakota.[36] 9 complete specimens.[36] A mactrid.
Eriphylopsis E. gregaria Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] 40 complete and incomplete specimens.[36] An astartid.
Gervillia G. sp. Bowman County, North Dakota.[36] One badly decorticated incomplete specimen.[36]
Inoceramus I. (Endocostea) barabini Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] About 25 specimens.[36] An inoceramid.
I. (Endocostea) fribrosa Bowman County, North Dakota.[36] 4 small incomplete specimens.[36] An inoceramid.
I. oblongus West of Cimarron.[6] An inoceramid.
I. sagensis Bowman County, North Dakota.[36] An inoceramid.
I. (Cremnoceramus) sp. Bowman County, North Dakota.[36] One decorticated incomplete specimen.[36] An inoceramid.
I. sp. A Bowman County, North Dakota.[36] One specimen that is badly decorticated.[36] An inoceramid.
I. sp. B Bowman County, North Dakota.[36] One slightly crushed specimen.[36] An inoceramid.
Limopsis L. parvula Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] About 40 specimens.[36] A limopsid.
Lucina L. (Lucina) occidentalis Bowman County, North Dakota.[36] 14 specimens.[36] A lucinid.
Mactra M. sp. Bowman County, North Dakota.[36] 4 broken incomplete molds.[36] A mactrid.
Malletia M. evansi Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] "7 badly decorticated incomplete specimens".[36] A malletiid.
M. sp. Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] 7 small, almost complete specimens.[36] A malletiid.
Modiolus M. meekii Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] 2 small incomplete internal molds.[36]
Nemodon N. sulcatinus Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] One badly weathered internal mold.[36] A parallelodontid.
Nucula N. sp. Bowman County, North Dakota.[36] "Five badly decorticated incomplete specimens".[36] A nuculid.
Ostrea O. congesta Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] 3 slightly crushed fragments.[36] An ostreid.
O. sp. Bowman County, North Dakota.[36] Numerous fragments.[36] An ostreid.
Protocardia P. (Leptocardia) rara Bowman County, North Dakota.[36] "10 complete, decorticated specimens".[36] A cardiid.
Pteria P. linguaeformis Bowman County, North Dakota.[36] About 15 broken specimens.[36] A pteriid.
?Syncyclonema ?S. rigida Bowman County, North Dakota.[36] 2 right valves.[36] An entoliid.

Brachiopods

Brachiopods reported from the Pierre Shale Formation
Genus Species Location Stratigraphic position Material Notes Images
Lingula L. sp. Wyoming.[1] Lower unnamed shale member.[1]

Cephalopods

Cephalopods reported from the Pierre Shale Formation
Genus Species Location Stratigraphic position Material Notes Images
Baculites B. baculus New Mexico.[6] Upper & uppermost Pierre Shale.[6] An ammonite.
B. cf. baculus Bowman County, North Dakota.[36] Baculites reesidei Range Zone.[36] 1 broken specimen.[36] An ammonite.
B. compressus At the Big Bend of the Missouri River, Buffalo County, South Dakota.[14] Uppermost DeGrey Formation.[14] Specimens associated with Globidens schurmanni.
B. cf. B. eliasi Northeastern New Mexico.[6] An ammonite.
B. grandis? Bowman County, North Dakota.[36] One large, crushed, badly weathered specimen.[36] An ammonite.
B. reesidei Bowman County, North Dakota.[36] Baculites reesidei Zone.[36] 11 broken specimens.[36] An ammonite.
B. sp. Bowman County, North Dakota.[36] Upper Baculites reesidei Zone.[36] 10 broken exfoliated specimens.[36] An ammonite.
B. sp. Northeastern New Mexico.[6][28] An ammonite.
Belemnitella B. bulbosa Upper Pierre Shale.[37] A belemnite also found in the Fox Hills Formation.
B.? sp. Meade County, South Dakota.[37] Baculites compressus zone.[37] 1 specimen (BHI-7009).[37] A belemnite.
Didymoceras D. cochleatum South Dakota & Wyoming.[38] Gregory & Red Bird Silty members.[38] Numerous fragments.[38] An ammonite.
D. nebrascense "Northwestern New Mexico through northeastern Montana".[39] An ammonite.
D. sp. Colfax County, New Mexico.[28] An ammonite.
Enchoteuthis E. cobbani Meade & Pennington counties, South Dakota.[37] Baculites cuneatus Zone & possibly the underlying B. compressus Zone.[37] 2 specimens.[37] A coleoid, originally described as Tusoteuthis cobbani.[40]
E. melanae Niobrara County, Wyoming.[37] Baculites obtusus zone, Sharon Springs Member.[37] Multiple specimens.[37] A coleoid.
Eutrephoceras E. dekayi Colorado, Bowman County, North Dakota and Colfax County, New Mexico.[41][28][36] Probably from the Baculites reesidei Zone.[36] A nautiloid, one specimen from Colorado showing signs of mosasaur predation.[41]
E. montanaensis Northeastern New Mexico.[6] A nautiloid.
Exiteloceras E. sp. Bowman County, North Dakota.[36] One fragmented body chamber.[36] A nostoceratid ammonite.
Hoploscaphites H. brevis Bowman County, North Dakota.[36] "Ten almost complete specimens and many fragments of early whorls".[36] An ammonite.
H. crassus Montana & Wyoming.[42] An ammonite.
H. criptonodosus Montana, Wyoming, Colorado, and possibly South Dakota.[43] "Upper part of the Baculites baculus Zone and overlying B. grandis Zone".[43] An ammonite also found in the Bearpaw Shale.
H. macer Montana, Wyoming & Colorado.[43] "Upper part of the Baculites baculus Zone and lower part of the overlying B. grandis Zone".[43] An ammonite also found in the Bearpaw Shale.
H. cf. H. nicolleti Bowman County, North Dakota.[36] 2 specimens.[36] An ammonite.
H. nodosus Near Raton, New Mexico.[6] "30-45 m below the top of the Pierre Shale".[6] An ammonite.
H. peterseni Montana & Wyoming.[42] An ammonite.
H. plenus Montana, Wyoming & North Dakota.[42] An ammonite.
H. quadrangularis Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] One broken shaft with aperture.[36] An ammonite.
H. sp. Bowman County, North Dakota.[36] One broken specimen.[36] An ammonite.
H. sp. Colfax County, New Mexico.[28] An ammonite.
Jeletzkytes J. nodosus At the Big Bend of the Missouri River, Buffalo County, South Dakota.[14] Uppermost DeGrey Formation.[14] Specimens associated with Globidens schurmanni.
Placenticeras P. intercalere Bowman County, North Dakota.[36] "One decorticated specimen badly fractured by calcite crystal growth".[36] An ammonite.
P. meeki Colfax County, New Mexico and Bowman County, North Dakota.[28][36] Baculites reesidei Zone.[36] An ammonite.
P. newberryi Colfax County, New Mexico.[28] An ammonite.
Ponteixites P. robustus Eastern Montana.[44] Now a junior synonym of Rhaeboceras.
Rhaeboceras R. burkholderi Dawson County, Montana.[45] Upper part of the Pierre Shale (Baculites eliasi zone).[45] An ammonite.
R. cedarense Dawson County, Montana.[45] Baculites baculus/grandis zone.[45] An ammonite.
R. robustus Eastern Montana.[44] An ammonite.
Scaphites S. nodosus Near Raton.[6] "About 15 m below the top of the Pierre Shale".[6] An ammonite.
Solenoceras S. sp. Bowman County, North Dakota.[36] 3 fragmented specimens.[36] A nostoceratid ammonite.
Tusoteuthis T. cobbani Meade & Pennington counties, South Dakota.[37] Baculites cuneatus Zone & possibly the underlying B. compressus Zone.[37] 2 specimens.[37] Moved to the genus Enchoteuthis.[40]
T. longa South Dakota.[37] Baculites compressus Zone.[37] A coleoid.

Echinoderms

Echinoderms reported from the Pierre Shale Formation
Genus Species Location Stratigraphic position Material Notes Images
Betelgeusia B. brezinai Pennington County, South Dakota.[46] Didymoceras cheyennensis Zone.[46] A starfish.
Brezinacantha B. tolis Pennington County, South Dakota.[47] Didymoceras cheyennensis Zone.[47] Multiple specimens.[47] A brittle star.
Coulonia Southern Colorado.[48] Top of the Pierre Shale.[48] An astropectinid starfish.
Eurysalenia E. minima Wyoming.[1] A sea urchin.
Lakotacrinus L. brezinai South Dakota.[49] A crinoid.
Pedicellasterinae? Gen. et. sp. indeterminate Pennington County, South Dakota[46] Didymoceras cheyennensis zone.[46] One small arm fragment (AMNH-FI 111853).[46] A starfish.

Gastropods

Gastropods
Genus Species Location Stratigraphic position Material Notes Images
Anchura? A.? sp. Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] "One broken, badly decorticated, medium-sized specimen".[36]
Anisomyon A. sexsulcatus? Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] "One badly decorticated specimen that is essentially an internal mold".[36] A siphonariid.
At the Big Bend of the Missouri River, Buffalo County, South Dakota.[14] Uppermost DeGrey Formation.[14] A siphonariid, specimens associated with Globidens schurmanni.
Atira A. nebrascensis Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] 3 decorticated specimens.[36]
Cylichna C. sp. Bowman County, North Dakota.[36] "Baculites reesidei Zone".[36] "One weathered specimen so badly decorticated that it is essentially a mold of the interior".[36]
Cylindrotruncatum C. cf. C. demursum Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] "One, small, broken, badly decorticated specimen".[36]
C. sp. Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] "Two medium-sized specimens; one in excellent condition and one internal mold".[36]
Drepanochilus D. sp. Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] Approximately 20 specimens.[36]
Euspira E. obliquata Bowman County, North Dakota.[36] Baculites reesidei Zone.[36] 25 nearly complete specimens.[36]
E. rectilabrum Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] 4 fairly complete shells.[36]
Pyrifuses P. sp. Bowman County, North Dakota.[36] 1 weathered external mold.[36]
Striaticostatum? S.? sp. Bowman County, North Dakota.[36] Baculites reesidei Zone.[36] One specimen.[36]
Turritella T. macnaryensis? Bowman County, North Dakota.[36] Probably from the Baculites reesidei Zone.[36] 2 specimens.[36]

Scaphopods

Scaphopods reported from the Pierre Shale Formation
Genus Species Location Stratigraphic position Material Notes Images
Dentalium D. gracile Bowman County, North Dakota.[36] "Probably from the Baculites reesidei Zone".[36] "3 nearly complete specimens & numerous fragments".[36]

References

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